JP6373052B2 - Liquid crystal display - Google Patents

Description

  The present invention relates to a liquid crystal display device.

  Liquid crystal display panels use TN (Twisted Nematic) mode, VA (Vertical Alignment) mode, IPS (In-Plane Switching) / FFS (Fringe Field Switching) mode, etc., but have a wide viewing angle and high contrast. Therefore, VA mode and IPS / FFS mode have become mainstream. However, the VA mode and the IPS / FFS mode are not sufficiently responsive, and there is a problem in displaying moving images. In addition, an OCB (Optically Compensated Bend) mode and a TBA (Transverse Bend Alignment) mode that can cope with moving image display with improved responsiveness have been proposed.

  While the OCB mode shows high-speed response, when the power is turned on, a transition operation from the splay alignment, which is the initial alignment, to the bend alignment at the time of driving (for example, applying a voltage of 10 V or more) is required. In addition, an initial transition drive circuit is required. For this reason, the OCB mode has a problem that it leads to an increase in cost and is not suitable for a mobile device with a limited power source.

  Further, the TBA mode has a problem that burn-in is likely to occur due to DC imbalance caused by the dielectric film because a dielectric film is provided on the common electrode on the color filter substrate side. In addition, the normal drive voltage (for example, about 5V) has a problem that the transmittance is lowered because the oblique electric field is weak.

JP 2010-217853 A

  The present invention provides a liquid crystal display device capable of improving response speed and transmittance.

A liquid crystal display device according to one embodiment of the present invention includes a first substrate and a second substrate which are arranged to face each other, and a p-type liquid crystal material which is sandwiched between the first and second substrates, in a state where no electric field is applied. wherein a liquid crystal layer takes a vertical orientation, is provided on the first substrate, a pixel electrode extending in a first direction, provided on the first substrate, the first and second electrode portions each extending in the first direction The first and second electrode portions are provided on the second substrate , the first common electrode being disposed on both sides of the pixel electrode in a second direction orthogonal to the first direction, and spaced apart from each other . And a second common electrode including third to fifth electrode portions each extending in the first direction . Each of the third and fourth electrode portions overlaps at least partially with the first and second electrode portions in planar projection, and the fifth electrode portion overlaps at least partially with the pixel electrode in planar projection.

A liquid crystal display device according to one embodiment of the present invention includes a first substrate and a second substrate which are arranged to face each other, and a p-type liquid crystal material which is sandwiched between the first and second substrates, in a state where no electric field is applied. A liquid crystal layer having vertical alignment; a pixel electrode provided on the first substrate; extending in a first direction; and first and second electrode portions provided on the first substrate, each extending in the first direction. The first and second electrode portions are provided on the second substrate, the first common electrode being disposed on both sides of the pixel electrode in a second direction orthogonal to the first direction, and spaced apart from each other. Each includes third and fourth electrode portions extending in the first direction, and each of the third and fourth electrode portions is at least partially overlapped with the first and second electrode portions in a planar projection. Electrode. The distance between the third electrode portion and the pixel electrode is smaller than the distance between the first electrode portion and the pixel electrode, and the distance between the fourth electrode portion and the pixel electrode is equal to the second electrode portion and the pixel electrode. It is smaller than the distance to the pixel electrode.

  ADVANTAGE OF THE INVENTION According to this invention, the liquid crystal display device which can improve a response speed and the transmittance | permeability can be provided.

1 is a block diagram of a liquid crystal display device according to a first embodiment of the present invention. FIG. 2 is a circuit diagram of a pixel array included in the liquid crystal display panel shown in FIG. 1. 1 is a schematic cross-sectional view of a liquid crystal display panel according to a first embodiment. The layout diagram of a liquid crystal display panel. The layout figure of the liquid crystal display panel except a reflecting film. Sectional drawing of the liquid crystal display panel along the AA 'line shown in FIG. Sectional drawing of the liquid crystal display panel along the BB 'line shown in FIG. The layout view and sectional drawing of CF board | substrate seen from the liquid crystal layer side. 6A and 6B illustrate an alignment state of a liquid crystal layer. The graph explaining the response speed of the liquid crystal display panel which concerns on an Example. The graph explaining the response speed in a 1st comparative example. The graph explaining the response speed in a 2nd comparative example. The layout drawing and sectional drawing of CF board concerning a 2nd embodiment of the present invention. 6A and 6B illustrate an alignment state of a liquid crystal layer. The layout figure of the TFT substrate which concerns on 3rd Embodiment of this invention. FIG. 3 is a layout diagram of a CF substrate viewed from the liquid crystal layer side. Sectional drawing of the liquid crystal display panel along CC 'line shown in FIG.15 and FIG.16. FIG. 6 is a schematic cross-sectional view of a liquid crystal display panel according to a fourth embodiment of the present invention. Sectional drawing of the liquid crystal display panel along the AA 'line which concerns on 4th Embodiment. Sectional drawing of the liquid crystal display panel along the BB 'line which concerns on 4th Embodiment. The figure explaining the parameter regarding the distance of a common electrode and a pixel electrode. The figure explaining the orientation state of the liquid crystal molecule which concerns on a comparative example. The figure explaining the orientation state of the liquid crystal molecule which concerns on 4th Embodiment. Sectional drawing of the liquid crystal display panel along the AA 'line which concerns on 5th Embodiment. Sectional drawing of the liquid crystal display panel along the BB 'line which concerns on 5th Embodiment.

  Hereinafter, embodiments will be described with reference to the drawings. However, it should be noted that the drawings are schematic or conceptual, and the dimensions and ratios of the drawings are not necessarily the same as the actual ones. Further, even when the same portion is represented between the drawings, the dimensional relationship and ratio may be represented differently. In particular, the following embodiments exemplify an apparatus and a method for embodying the technical idea of the present invention, and the technical idea of the present invention depends on the shape, structure, arrangement, etc. of components. Is not specified. In the following description, elements having the same function and configuration are denoted by the same reference numerals, and redundant description will be given only when necessary.

[First Embodiment]
[1. Circuit configuration of liquid crystal display device]
First, an example of the circuit configuration of the liquid crystal display device 10 will be described. FIG. 1 is a block diagram of a liquid crystal display device 10 according to the first embodiment of the present invention. In the present embodiment, the active matrix type liquid crystal display device 10 will be described as an example.

  The liquid crystal display device 10 includes a liquid crystal display panel 11, a scanning driver (scanning line driving circuit) 12, a signal driver (signal line driving circuit) 13, a common voltage supply circuit 14, a voltage generation circuit 15, and a control circuit 16.

  The liquid crystal display panel 11 is provided with a plurality of scanning lines GL each extending in the row direction (X direction) and a plurality of signal lines SL each extending in the column direction (Y direction). A pixel 17 is disposed in each of the intersecting regions of the plurality of scanning lines GL and the plurality of signal lines SL. The plurality of pixels 17 are arranged in a matrix.

  FIG. 2 is a circuit diagram of a pixel array included in the liquid crystal display panel 11 shown in FIG. In FIG. 2, four pixels are extracted and shown. The pixel 17 includes a switching element 18, a liquid crystal capacitor Clc, and a storage capacitor Cs. For example, a TFT (Thin Film Transistor) is used as the switching element 18.

  The source of the TFT 18 is electrically connected to the signal line SL. The gate of the TFT 18 is electrically connected to the scanning line GL. The drain of the TFT 18 is electrically connected to the liquid crystal capacitor Clc. The liquid crystal capacitor Clc includes a pixel electrode, a common electrode, and a liquid crystal layer sandwiched between them.

  The storage capacitor Cs is connected in parallel to the liquid crystal capacitor Clc. The storage capacitor Cs has a function of suppressing the potential fluctuation generated in the pixel electrode and holding the drive voltage applied to the pixel electrode until the drive voltage corresponding to the next signal is applied. The storage capacitor Cs includes a pixel electrode, a storage electrode (storage capacitor line), and an insulating film sandwiched between them. A common voltage Vcom is applied to the common electrode and the storage electrode by the common voltage supply circuit 14.

  In FIG. 1, the scanning driver 12 is connected to a plurality of scanning lines GL and receives a vertical control signal Vs from the control circuit 16. The scanning driver 12 applies a scanning signal for controlling on / off of the TFT 18 to the scanning line GL based on the vertical control signal Vs.

  The signal driver 13 is connected to the plurality of signal lines SL, and receives the horizontal control signal Hs and the display data D2 from the control circuit 16. The signal driver 13 applies a gradation signal (drive voltage) corresponding to the display data D2 to the signal line SL based on the horizontal control signal Hs. The common voltage supply circuit 14 generates a common voltage Vcom and supplies it to the liquid crystal display panel 11.

  The control circuit 16 receives image data D1 from the outside. The control circuit 16 generates display data D2 from the image data D1. Further, the control circuit 16 generates an inversion signal Pol every predetermined period (for example, one frame, one field, or one line) in order to perform AC driving (inversion driving). Then, the control circuit 16 sends the vertical control signal Vs to the scanning driver 12, sends the horizontal control signal Hs, display data D 2, and the inverted signal Pol to the signal driver 13, and sends the inverted signal Pol to the common voltage supply circuit 14. In response to this, the signal driver 13 inverts the polarity of the drive voltage every time the inverted signal Pol is input. Similarly, the common voltage supply circuit 14 inverts the polarity of the common voltage Vcom every time the inverted signal Pol is input. Thereby, the alternating current drive of the liquid crystal display panel 11 is realizable.

  The voltage generation circuit 15 generates a gate voltage necessary for generating a scanning signal and supplies it to the scanning driver 12. The voltage generation circuit 15 generates a drive voltage necessary for driving the pixel and supplies the drive voltage to the signal driver 13. In addition, the voltage generation circuit 15 generates various voltages necessary for the operation of the liquid crystal display device 10 and supplies them to each circuit unit as necessary.

  In the liquid crystal display device 10 configured as described above, when the TFT 18 included in an arbitrary pixel 17 is turned on, a driving voltage is applied to the pixel electrode via the signal line SL, and the voltage between the driving voltage and the common voltage Vcom is determined. The alignment state of the liquid crystal changes according to the difference. Thereby, the transmission state of the light incident on the liquid crystal display panel 11 from the light source is changed, and image display is performed.

[2. Configuration of LCD panel]
FIG. 3 is a schematic cross-sectional view of the liquid crystal display panel 11 according to the first embodiment of the present invention.
A surface light source (backlight) 20 is disposed opposite to the surface opposite to the display surface of the liquid crystal display panel 11. For the backlight 20, for example, a sidelight type (edge light type) backlight device is used. That is, the backlight 20 is configured such that a plurality of light emitting elements such as LEDs (light emitting diodes) are incident from the end face of the light guide plate, and light is emitted from one plate surface of the light guide plate toward the pixel array. . For example, the backlight 20 is configured by laminating a reflection sheet, a light guide plate, a diffusion sheet, and a prism sheet.

  The liquid crystal display panel 11 includes a TFT substrate 21 on which TFTs as switching elements, pixel electrodes, and the like are formed, and a color filter substrate (CF substrate) on which a color filter and a common electrode are formed and disposed opposite to the TFT substrate 21. 22 and a liquid crystal layer 23 sandwiched between the TFT substrate 21 and the CF substrate 22. Each of the TFT substrate 21 and the CF substrate 22 is composed of a transparent substrate (for example, a glass substrate).

  The liquid crystal layer 23 is made of a liquid crystal material sealed with a sealing material (not shown) that bonds the TFT substrate 21 and the CF substrate 22 together. The cell gap of the liquid crystal layer 23 is controlled by a spacer (not shown) provided in the liquid crystal layer 23. In the liquid crystal material, the orientation of liquid crystal molecules is controlled according to the electric field, and the optical characteristics change. In this embodiment, the liquid crystal layer 23 is made of a positive (p-type) liquid crystal material, and is aligned substantially perpendicular to the substrate surface in a state where no voltage (electric field) is applied (initial alignment state) (vertical alignment). To be set). Therefore, in the liquid crystal layer 23 of the present embodiment, the major axis (director) of the liquid crystal molecules is aligned vertically when there is no voltage (no electric field), and the director of the liquid crystal molecules faces the electric field direction when a voltage is applied (electric field application). Lean.

  A TFT 18 and a pixel electrode 24 are provided for each pixel 17 on the liquid crystal layer 23 side of the TFT substrate 21. The TFT substrate 21 is provided with a common electrode 25 (including common electrodes 25-1 and 25-2) formed so as to sandwich or surround the pixel electrode 24. Further, an alignment film 26 is provided on the TFT substrate 21 so as to cover the pixel electrode 24 and the common electrodes 25-1 and 25-2.

  A color filter 27 is provided on the liquid crystal layer 23 side of the CF substrate 22. The color filter 27 includes a plurality of coloring filters (coloring members), and specifically includes a plurality of red filters 27-R, a plurality of green filters 27-G, and a plurality of blue filters 27-B. A general color filter is composed of three primary colors of light, red (R), green (G), and blue (B). A set of three colors R, G, and B adjacent to each other is a display unit (referred to as a pixel or a pixel), and any single color portion of R, G, or B in one pixel is a subpixel (subpixel). This is a minimum drive unit called a pixel. The TFT 18 and the pixel electrode 24 are provided for each subpixel. In the following description, a subpixel is referred to as a pixel unless it is particularly necessary to distinguish between a pixel and a subpixel.

  A black matrix (light-shielding film) BM for light shielding is provided at the boundary between the pixels (sub-pixels). For example, the black matrix BM is formed in a mesh shape. The black matrix BM is provided, for example, to shield unnecessary light between the coloring members and improve contrast.

  On the color filter 27 and the black matrix BM, the common electrode 28 (including the common electrodes 28-1 and 28-2) formed so as to overlap the common electrodes 25-1 and 25-2 in a planar projection (plan view). Is provided. That is, the common electrode 28 on the CF substrate 22 side is not formed in a planar shape, but is formed in a linear shape or a lattice shape. An alignment film 29 is provided on the CF substrate 22 so as to cover the common electrodes 28-1 and 28-2.

  The circularly polarizing plates 30 and 33 are provided so as to sandwich the TFT substrate 21 and the CF substrate 22. The circularly polarizing plate 30 circularly polarizes incident light from the backlight 20. The circularly polarizing plate 33 circularly polarizes incident light from the display surface and linearly polarizes transmitted light transmitted through the liquid crystal layer 23. The circularly polarizing plate 30 includes a retardation plate 31 and a polarizing plate 32. The circularly polarizing plate 33 includes a retardation plate 34 and a polarizing plate 35.

  The polarizing plates 32 and 35 have a transmission axis and an absorption axis orthogonal to each other in a plane orthogonal to the light traveling direction. The polarizing plates 32 and 35 transmit linearly polarized light (linearly polarized light component) having a vibration surface parallel to the transmission axis out of light having vibration surfaces in random directions, and have a vibration surface parallel to the absorption axis. Absorbs linearly polarized light (linearly polarized light component). The polarizing plates 32 and 35 are disposed so that their transmission axes are orthogonal to each other, that is, in an orthogonal Nicol state.

  The phase difference plates 31 and 34 have refractive index anisotropy, and have a slow axis and a fast axis that are perpendicular to each other in a plane perpendicular to the light traveling direction. The phase difference plates 31 and 34 have a predetermined retardation (a phase difference of λ / 4 when λ is a wavelength of light transmitted) between light of a predetermined wavelength that transmits the slow axis and the fast axis, respectively. Has the function to give. That is, the phase difference plates 31 and 34 are composed of λ / 4 plates. The slow axis of the phase difference plate 31 is set to form an angle of 45 ° with respect to the transmission axis of the polarizing plate 32. The slow axis of the phase difference plate 34 is set to make an angle of 45 ° with respect to the transmission axis of the polarizing plate 35.

[3. Specific example of the liquid crystal display panel 11]
Next, a more specific configuration example of the liquid crystal display panel 11 will be described. Hereinafter, the transflective liquid crystal display panel 11 will be described as an example. The transflective liquid crystal display panel 11 has a reflection area for displaying an image by reflecting external light and a transmission area for displaying an image by transmitting backlight light in one pixel.

  FIG. 4 is a layout diagram of the liquid crystal display panel 11. The layout diagram of FIG. 4 mainly shows the configuration of the TFT substrate 21 and shows the layout for one pixel. FIG. 5 is a layout diagram of the liquid crystal display panel 11 excluding the reflective film from FIG. FIG. 6 is a cross-sectional view of the liquid crystal display panel 11 taken along line AA ′ shown in FIG. FIG. 7 is a cross-sectional view of the liquid crystal display panel 11 along the line BB ′ shown in FIG. 6 and 7, the circularly polarizing plates 30 and 33 shown in FIG. 3 and the alignment films 26 and 29 are not shown.

  On the TFT substrate 21, a scanning line (gate electrode) GL extending in the X direction is provided. The scanning line GL functions as a gate electrode of the TFT 18. A storage capacitor line 40 extending in the X direction is provided on the TFT substrate 21. The storage capacitor line 40 constitutes the storage capacitor Cs shown in FIG. An insulating film 41 is provided on the TFT substrate 21 so as to cover the gate electrode GL and the storage capacitor line 40. The insulating film 41 on the gate electrode GL functions as a gate insulating film of the TFT 18.

  A semiconductor layer 42 is provided above the gate electrode GL and on the insulating film 41. The semiconductor layer 42 is made of, for example, amorphous silicon or polysilicon. A source electrode 43 and a drain electrode 44 are provided on both sides of the gate electrode GL and on the insulating film 41. Each of the source electrode 43 and the drain electrode 44 is in partial contact with the semiconductor layer 42. The TFT 18 includes a gate electrode GL, a gate insulating film 41, a source electrode 43, and a drain electrode 44.

  A signal line SL extending in the Y direction is provided on the insulating film 41. The signal line SL is electrically connected to the source electrode 43. The signal line SL is disposed below the black matrix BK.

  An insulating film 45 is provided on the TFT 18 and the signal line SL. A reflective film 46 is provided on the insulating film 45 so as to cover the TFT 18. The reflective area of the pixel 17 corresponds to the area where the reflective film 46 is formed. The transmissive region of the pixel 17 corresponds to a region other than the region where the reflective film 46 and the storage capacitor line 40 are formed. An insulating film 47 is provided on the reflective film 46.

  A pixel electrode 24 and a common electrode 25 are provided on the insulating film 47. The pixel electrode 24 is formed linearly so as to extend in the Y direction at the center of the pixel 17 and is electrically connected to the drain electrode 44 by a contact plug 48. The width of the pixel electrode 24 is preferably narrower, but is actually set to about 2 to 3 μm in consideration of restrictions due to the manufacturing method. In the configuration example of FIG. 4, the drain electrode 44 includes a first electrode portion that partially contacts the semiconductor layer 42, and a second electrode portion that extends from the first electrode portion to below the contact plug 48. Consists of

  The common electrode 25 is formed so as to sandwich or surround the pixel electrode 24 with a predetermined interval. In the configuration example of FIG. 4, the common electrode 25 is formed so as to surround the pixel electrode 24. Specifically, the common electrode 25 is arranged so as to sandwich the pixel electrode 24 from both sides in the X direction at a predetermined interval, and each of the common electrodes 25 extends linearly in the Y direction. Including a basic unit that is electrically connected to the common electrodes 25-1 and 25-2 and includes linear common electrodes 25-3 and 25-4 each extending in the X direction. It is arranged in a grid pattern and corresponding to the pixels. The distance between the pixel electrode 24 and the common electrode 25 is preferably 15 μm or less, and more preferably about 3 to 4 μm. The common electrodes 25-1 and 25-2 are formed so as to cover the signal line SL in the planar projection. Thereby, it is possible to prevent an unnecessary electric field due to the signal line SL from being applied to the liquid crystal layer 23.

  FIG. 8 is a layout view and a sectional view of the CF substrate 22 as viewed from the liquid crystal layer 23 side. FIG. 8A is a layout diagram of the CF substrate 22, and FIG. 8B is a cross-sectional view of the CF substrate 22 taken along the line CC ′ shown in FIG. 8A. FIG. 8 shows a layout for three pixels. FIG. 8 illustrates a stripe-arranged color filter 27 as an example.

  On the CF substrate 22, a grid-like black matrix BM arranged at the boundary of the pixels is provided. A color filter 27 (including a red filter 27-R, a green filter 27-G, and a blue filter 27-B) is provided on the CF substrate 22 and the black matrix BM.

  On the color filter 27, a grid-like common electrode 28 disposed at a pixel boundary is provided. The common electrode 28 has substantially the same planar shape as the common electrode 25 formed on the TFT substrate 21 side, and is disposed so as to overlap the common electrode 25 in planar projection. Specifically, the common electrode 28 electrically connects the linear common electrodes 28-1 and 28-2 and the common electrodes 28-1 and 28-2 that sandwich the pixel electrode 24 from both sides in the X direction and extend in the Y direction. And includes a basic unit composed of linear common electrodes 28-3 and 28-4 extending in the X direction, and the basic units are arranged in a lattice shape in four directions and corresponding to the pixels. Is done.

  In the present embodiment, the expression that the common electrode 25 and the common electrode 28 overlap each other includes a case where the common electrode 25 and the common electrode 28 are completely overlapped in a planar projection and a case where the common electrode 25 and the common electrode 28 overlap partially. including. The thickness of the common electrode 28 may be the same as or different from the thickness of the common electrode 25. When the liquid crystal display panel 11 is configured so that the thickness of the common electrode 25 and the thickness of the common electrode 28 are different, the common electrode 25 and the common electrode 28 are formed so that at least a part thereof overlaps with each other in a portion facing each other. The In addition, the expression that the common electrode 25 and the common electrode 28 overlap each other is formed by being shifted from each other due to an error or misalignment caused by the manufacturing method and manufacturing process, and at least a part of each other is allowed to overlap. Shall.

  The pixel electrode 24, the contact plug 48, and the common electrodes 25 and 28 are made of transparent electrodes, and for example, ITO (indium tin oxide) is used. The insulating films 41, 45, and 47 are made of a transparent insulating material, and for example, silicon nitride (SiN) is used. As the reflective film 46, for example, aluminum (Al), silver (Ag), or an alloy containing any of these is used. The source electrode 43, the drain electrode 44, the scanning line GL, the signal line SL, and the storage capacitor line 40 are, for example, aluminum (Al), molybdenum (Mo), chromium (Cr), tungsten (W), or these An alloy containing one or more of the above is used.

  In the above description, a configuration example of the transflective liquid crystal display panel 11 including the reflective region and the transmissive region has been described. However, the present embodiment can also be applied to the transmissive liquid crystal display panel 11 that does not include a reflective region.

  The transmissive liquid crystal display panel 11 is configured by removing the reflective film 46 from the configuration of the transflective liquid crystal display panel 11, that is, the layout diagram of the transmissive liquid crystal display panel 11 is the same as FIG. Further, the cross-sectional view of the transmissive liquid crystal display panel 11 is the same as the cross-sectional view excluding the reflective film 46 of FIG.

[4. Operation]
Next, the operation of the liquid crystal display device 10 configured as described above will be described. First, display in a state where no electric field is applied to the liquid crystal layer 23 will be described. FIG. 9A is a diagram for explaining the alignment state of the liquid crystal molecules in the state where no electric field is applied to the liquid crystal layer 23.

  The common voltage supply circuit 14 applies a common voltage Vcom (for example, 0 V) to the common electrodes 25 and 28, and the signal driver 13 applies the common voltage Vcom to the pixel electrode 24. In the case of the transflective liquid crystal display panel 11, the common voltage supply circuit 14 also applies a common voltage Vcom to the reflective film 46. Thereby, it is possible to prevent an electric field due to the wiring and electrodes below the reflective film 46 from being applied to the liquid crystal layer 23.

  In the voltage relationship of FIG. 9A, no electric field is applied to the liquid crystal layer 23 (off state), and the liquid crystal molecules maintain the initial alignment. That is, in this embodiment, the liquid crystal molecules are aligned substantially perpendicular to the substrate surface. In this OFF state, incident light from the backlight 20 is sequentially absorbed by the circularly polarizing plate 33 after passing through the circularly polarizing plate 30 and the liquid crystal layer 23 having a substantially zero retardation. As a result, the liquid crystal display device 10 displays black.

  Next, display in a state where an electric field is applied to the liquid crystal layer 23 will be described. FIG. 9B is a diagram for explaining the alignment state of the liquid crystal molecules in the state where an electric field is applied to the liquid crystal layer 23. The common voltage supply circuit 14 applies a common voltage Vcom (for example, 0 V) to the common electrodes 25 and 28, and the signal driver 13 applies a drive voltage (for example, 5 V) higher than the common voltage Vcom to the pixel electrode 24.

  In the voltage relationship (ON state) of FIG. 9B, the liquid crystal layer 23 has a lateral electric field generated between the pixel electrode 24 and the common electrode 25 and an oblique electric field generated between the pixel electrode 24 and the common electrode 28. Are applied. As a result, the liquid crystal layer 23 takes half-bend alignment (one side half of the bend alignment), and the liquid crystal molecules are inclined in the direction of the common electrodes 25 and 28 with respect to the normal passing through the center of the pixel electrode 24. Specifically, the closer to the pixel electrode 24 and the common electrode 25, the larger the inclination of the liquid crystal molecules, and the closer the pixel electrode 24 to the common electrode 28, the smaller the inclination of the liquid crystal molecules. Further, since the common electrode 28 is disposed obliquely from the pixel electrode 24, a larger oblique electric field can be applied to the liquid crystal layer 23. Thereby, the liquid crystal molecules above the pixel electrode 24 can also be tilted, so that the transmittance can be improved.

  In this ON state, incident light from the backlight 20 passes through the circularly polarizing plate 30 and then passes through the liquid crystal layer 23 to be given a predetermined retardation. Further, the transmitted light that passes through the liquid crystal layer 23 is circularly polarized light. It passes through the plate 33. As a result, the liquid crystal display device 10 performs white display (actually, color display corresponding to the color filter).

[5. effect]
As described above in detail, in the first embodiment, the liquid crystal layer 23 is made of a p-type (positive) liquid crystal material, and aligns liquid crystal molecules substantially vertically in the state where an electric field is not applied. Further, the TFT substrate 21 is provided with a linear pixel electrode 24 and a common electrode 25 formed so as to surround or sandwich the pixel electrode 24 with a predetermined interval. Further, the CF substrate 22 is provided with a common electrode 28 having substantially the same planar shape as the common electrode 25 and formed so as to at least partially overlap the common electrode 25.

  Therefore, according to the first embodiment, when an electric field is applied to the liquid crystal layer 23, the liquid crystal molecules take a bend alignment (specifically, a half bend alignment), and therefore, a VA (Vertical Alignment) mode and IPS Compared with (In-Plane Switching) / FFS (Fringe Field Switching) mode, the response speed of the liquid crystal display panel 11 can be further increased.

  FIG. 10 is a graph for explaining the response speed of the liquid crystal display panel 11 according to the present embodiment. In FIG. 10, the X axis represents the original gradation, the Y axis represents the previous gradation, and the Z axis represents the response speed (msec). The original gradation means the gradation before changing the gradation. The previous gradation means a gradation after changing the gradation. The numbers on the X axis and the Y axis represent gradations, and here, the response speed when displaying 64 gradations (0 gradations to 63 gradations) is shown. The 0 gradation is black (BK) and the 63 gradation is white (W).

  The graph shown in FIG. 10 is obtained when the display is changed from the first gradation (original gradation) to the second gradation (destination gradation) in the first gradation described on the X axis (original gradation). The response speed can be understood from the height of the bar graph at the position where the numeral and the numeral of the second gradation described on the Y-axis (first gradation) intersect.

  FIG. 11 is a graph for explaining the response speed in the VA mode liquid crystal display panel (first comparative example). FIG. 12 is a graph for explaining the response speed in the FFS mode liquid crystal display panel (second comparative example). It can be understood that the liquid crystal display panel 11 of the present embodiment shown in FIG. 10 has an improved response speed compared to the first comparative example (FIG. 11) and the second comparative example (FIG. 12).

  Further, it is not necessary to form a dielectric film for adjusting the electric field applied to the liquid crystal layer 23, which is required in the conventional TBA (Transverse Bend Alignment) mode, on the common electrode 28 on the CF substrate 22 side. . Thereby, an afterimage (so-called burn-in) caused by DC (direct current) imbalance can be suppressed.

  Further, by arranging the common electrode 28 on the CF substrate 22 side so as to overlap the common electrode 25 on the TFT substrate 21 side in the planar projection, the pixel electrode 24 on the TFT substrate 21 side and the common electrode 28 on the CF substrate 22 side An oblique electric field is generated more strongly between the two. Thereby, since the liquid crystal molecules can be tilted so as to have a desired half-bend alignment, the transmittance can be improved.

  In addition, since the transmittance is low in the TBA mode, it is difficult to reduce the cell gap from the usual 4 μm. However, by adopting the structure of this embodiment, the cell gap can be reduced to about 3 μm, and the response speed can be further increased.

  In addition, when the cell gap is about 4 μm, the viewing angle becomes narrow in the current circularly polarizing plate (consisting of a polarizing plate and a retardation plate (λ / 4 plate)) due to the retardation Δnd of the liquid crystal layer. It was difficult to use a polarizing plate. However, since the cell gap can be reduced in the liquid crystal display panel 11 of the present embodiment, a circularly polarizing plate can be used without deteriorating the viewing angle. Further, by arranging the circularly polarizing plate on the liquid crystal display panel 11, it is possible to take out light in an area where the liquid crystal molecules are tilted in the axial direction of the polarizing plate, which could not be taken out by the linear polarizing plate, and further improve the transmittance. Is possible. Furthermore, since the optical design of the reflective display can be optimized, it can be applied to a transflective liquid crystal display panel.

[Second Embodiment]
FIG. 13 is a layout view and a cross-sectional view of the CF substrate 22 according to the second embodiment of the present invention. FIG. 13A is a layout diagram of the CF substrate 22, and FIG. 13B is a cross-sectional view of the CF substrate 22 taken along the line CC ′ shown in FIG. FIG. 13 shows a layout for three pixels. FIG. 13 shows a stripe-arranged color filter 27 as an example.

  On the color filter 27, an electrode portion formed so as to overlap the common electrode 25 formed on the TFT substrate 21 side in the planar projection and a pixel electrode 24 formed on the TFT substrate 21 side so as to overlap in the planar projection. A common electrode 28 including the formed electrode portion is provided. Specifically, the common electrode 28 electrically connects the linear common electrodes 28-1 and 28-2 and the common electrodes 28-1 and 28-2 that sandwich the pixel electrode 24 from both sides in the X direction and extend in the Y direction. And linear common electrodes 28-3 and 28-4 extending in the X direction, and a common electrode 28-5 disposed at a predetermined interval between the common electrodes 28-1 and 28-2. The basic unit is configured, and the basic unit is arranged in a grid pattern on all sides and corresponding to the pixels. The common electrodes 28-1 to 28-4 are arranged so as to overlap with the common electrode 25 formed on the TFT substrate 21 side in the planar projection. The common electrode 28-5 is arranged so as to overlap with the pixel electrode 24 formed on the TFT substrate 21 side in a planar projection.

  Next, the operation of the liquid crystal display device 10 configured as described above will be described. FIG. 14A is a diagram illustrating the alignment state of liquid crystal molecules in a state where no electric field is applied to the liquid crystal layer 23 (off state). The common voltage supply circuit 14 applies a common voltage Vcom (for example, 0 V) to the common electrodes 25 and 28, and the signal driver 13 applies the common voltage Vcom to the pixel electrode 24. The display of the liquid crystal display device 10 in the off state is the same as in the case of FIG.

  FIG. 14B is a diagram for explaining the alignment state of the liquid crystal molecules when an electric field is applied to the liquid crystal layer 23 (ON state). The common voltage supply circuit 14 applies a common voltage Vcom (for example, 0 V) to the common electrodes 25 and 28, and the signal driver 13 applies a drive voltage (for example, 5 V) higher than the common voltage Vcom to the pixel electrode 24.

  Even in this on-state, the liquid crystal layer 23 takes half-bend alignment as in the first embodiment. Further, since an electric field in the vertical direction (vertical direction) is applied between the pixel electrode 24 and the common electrode 28-5, liquid crystal molecules existing between the pixel electrode 24 and the common electrode 28-5 are vertical. Take orientation. Thereby, since the orientation of the liquid crystal layer 23 as a whole can be stabilized, display defects that occur when the display surface of the liquid crystal display panel 11 is pressed (when the surface is pressed) can be suppressed. Other effects are the same as those of the first embodiment.

[Third Embodiment]
The third embodiment is a configuration example of the liquid crystal display panel 11 when the pixels 17 include a plurality of linear pixel electrodes 24.

  FIG. 15 is a layout diagram of the TFT substrate 21 according to the third embodiment of the present invention. FIG. 16 is a layout diagram of the CF substrate 22 as viewed from the liquid crystal layer 23 side. FIG. 17 is a cross-sectional view of the liquid crystal display panel 11 taken along the line CC ′ shown in FIGS. 15 and 16. In the cross-sectional view of FIG. 17, the circularly polarizing plates 30 and 33 and the alignment films 26 and 29 shown in FIG.

  In FIG. 15, the pixel electrode 24 provided on the TFT substrate 21 is electrically connected to the linear pixel electrodes 24-1 and 24-2 and the pixel electrodes 24-1 and 24-2 each extending in the Y direction. Connecting portion 24-3. The connection portion 24-3 is electrically connected to the drain electrode 44 by the contact plug 48.

  The common electrode 25 provided on the TFT substrate 21 is arranged so as to sandwich the pixel electrodes 24-1 and 24-2 from both sides in the X direction with a predetermined interval, and each linear common electrode 25 extends in the Y direction. -1 and 25-2, the common electrodes 25-1 and 25-2 are electrically connected to each other, and the linear common electrodes 25-3 and 25-4 extending in the X direction and the pixel electrodes 24-1 and 24- Including a basic unit composed of a common electrode 25-5 which is arranged in a straight line extending in the Y direction and is electrically connected to the common electrode 25-4. The basic units are arranged in a grid pattern on all sides and corresponding to the pixels. That is, the common electrodes 25-1 and 25-5 are arranged so as to sandwich the pixel electrode 24-1 provided on the TFT substrate 21 from the both sides in the X direction with a predetermined interval, and the common electrodes 25-2 and 25-. 5 is arranged so as to sandwich the pixel electrode 24-2 provided on the TFT substrate 21 from both sides. Further, the common electrodes 25-1 and 25-2 are arranged so as to cover the signal line SL in the planar projection.

  In FIG. 16, on the color filter 27, a common electrode 28 having substantially the same planar shape as the common electrode 25 formed on the TFT substrate 21 side and disposed so as to overlap the common electrode 25 in the planar projection is provided. . That is, the common electrode 28 includes common electrodes 28-1 to 28-5, and the common electrodes 28-1 to 28-5 are arranged so as to overlap the common electrodes 25-1 to 25-5 in the planar projection, respectively. The

  FIG. 15 shows a configuration example of the transflective liquid crystal display panel 11 including a reflective region and a transmissive region. However, as in the first embodiment, it is also possible to apply this embodiment to the transmissive liquid crystal display panel 11 that does not include a reflective region. The transmissive liquid crystal display panel 11 is configured except for the reflective film 46 of FIGS. 15 and 17.

  According to the third embodiment, between the common electrode 25-1 and the pixel electrode 24-1, between the pixel electrode 24-1 and the common electrode 25-5, and between the common electrode 25-5 and the pixel electrode 24-2. In the meantime, the liquid crystal layer can be set to a half-bend alignment in each of the pixel electrode 24-2 and the common electrode 25-2. Thus, even when the pixel 17 includes a plurality of linear pixel electrodes 24, the same operation as in the first embodiment can be realized. Of course, three or more linear pixel electrodes may be arranged in the pixel 17. Moreover, it is also possible to apply 2nd Embodiment to 3rd Embodiment.

[Fourth Embodiment]
In the fourth embodiment, the distance between the common electrode 28 on the CF substrate 22 side and the pixel electrode 24 is made smaller than the distance between the common electrode 25 on the TFT substrate 21 side and the pixel electrode 24. Then, the oblique electric field between the common electrode 28 and the pixel electrode 24 is made larger than the lateral electric field between the common electrode 25 and the pixel electrode 24. Accordingly, a desired alignment state is realized by suppressing alignment defects of the liquid crystal.

[1. Configuration of LCD panel]
FIG. 18 is a schematic cross-sectional view of a liquid crystal display panel 11 according to the fourth embodiment of the present invention. The layout diagram for one pixel is the same as FIG. 4 (semi-transmissive type) shown in the first embodiment. FIG. 19 is a cross-sectional view of the liquid crystal display panel 11 taken along line AA ′ shown in FIG. FIG. 20 is a cross-sectional view of the liquid crystal display panel 11 taken along the line BB ′ shown in FIG. 19 and 20, the circularly polarizing plates 30 and 33 and the alignment films 26 and 29 shown in FIG. 18 are not shown.

  On the insulating film 47 formed on the TFT substrate 21, a pixel electrode 24 extending in the Y direction and a common electrode 25 (common electrodes 25-1 to 25-4) surrounding the pixel electrode 24 are provided. As described above, the common electrode 25 may be configured to sandwich the pixel electrode 24 from the X direction. The common electrodes 25-1 and 25-2 are formed so as to cover the signal line SL in planar projection (plan view). Thereby, it is possible to prevent an unnecessary electric field due to the signal line SL from being applied to the liquid crystal layer 23.

  On the color filter 27 and the black matrix BM formed on the CF substrate 22, common electrodes 28 (common electrodes 28-1 to 28-4) are provided. As shown in FIG. 19, the common electrodes 28-1 and 28-2 are arranged so as to overlap the common electrodes 25-1 and 25-2 in the planar projection. The widths of the common electrodes 28-1 and 28-1 are set larger than the widths of the common electrodes 25-1 and 25-2. Similarly, as shown in FIG. 20, the common electrodes 28-3 and 28-4 are arranged so as to overlap the common electrodes 25-3 and 25-4 in the planar projection. The widths of the common electrodes 28-3 and 28-4 are set larger than the widths of the common electrodes 25-3 and 25-4.

  FIG. 21 is a diagram illustrating parameters regarding the distance between the common electrodes 25 and 28 and the pixel electrode 24. “A” is the distance between the pixel electrode 24 and the common electrode 25-2. “B” is the distance between the common electrode 25-2 and the common electrode 28-2, that is, corresponds to the cell gap. “C” is the distance between the pixel electrode 24 and the common electrode 28-2, specifically, the end of the pixel electrode 24 on the common electrode 28-2 side and the common electrode 28-2 on the pixel electrode 24 side. The diagonal distance between the edges. “D” is a horizontal distance between the end of the common electrode 28-2 on the pixel electrode 24 side and the end of the common electrode 25-2 on the pixel electrode 24 side.

The distance c is represented by the following formula (1).

Here, the distance c is set smaller than the distance a. Since c <a, the distance d is expressed by the following formula (2).

  Note that 0 <d <a.

  Also, the conditions for the common electrodes 25-1, 25-3, 25-4, 28-1, 28-3, 28-4 are the same as those for the common electrodes 25-2, 28-2 shown in FIG. Set to meet.

[2. Operation]
First, the operation of the liquid crystal display panel according to the comparative example will be described. FIG. 22 is a diagram for explaining the alignment state of the liquid crystal molecules according to the comparative example. FIG. 22 shows a state where an electric field is applied to the liquid crystal layer (ON state). In the ON state, a common voltage Vcom (for example, 0V) is applied to the common electrodes 25 and 28, and a drive voltage (for example, 5V) higher than the common voltage Vcom is applied to the pixel electrode 24. The state in which an electric field is not applied to the liquid crystal layer (off state) is the same as FIG.

  In the comparative example, the width of the common electrode 28 on the CF substrate 22 side is smaller than the width of the common electrode 25 on the TFT substrate 21 side. Further, when the common electrode 28 on the CF substrate 22 side is disposed inside the common electrode 25 on the TFT substrate 21 side (in the direction away from the pixel electrode 24) due to misalignment of the upper and lower substrates, at least the common electrode 28 in FIG. -1 and 28-2, the same positional relationship is generated. In this case, since the distance between the common electrode 28 and the pixel electrode 24 is larger than the distance between the common electrode 25 and the pixel electrode 24, the oblique electric field applied between the common electrode 28 and the pixel electrode 24 is The horizontal electric field applied between the pixel electrode 24 and the pixel electrode 24 becomes smaller.

  If the oblique electric field is smaller than the lateral electric field, liquid crystal alignment defects occur in the domains in the liquid crystal layer 23 shown in FIG. For example, since the liquid crystal molecules on both sides of the domain are tilted toward the domain side, the liquid crystal molecules in the domain cannot be tilted toward the common electrode 28 and are in a standing state, and further, the liquid crystal molecules in the domain move during display. There is a possibility that. In this domain, alignment failure of the liquid crystal occurs, and a desired alignment (half-bend alignment) cannot be realized. As a result, this domain causes display unevenness and afterimage.

  FIG. 23 is a diagram for explaining the alignment state of the liquid crystal molecules according to the present embodiment. FIG. 23 shows a state in which an electric field is applied to the liquid crystal layer (ON state). In the ON state, the common voltage supply circuit 14 applies a common voltage Vcom (for example, 0 V) to the common electrodes 25 and 28, and the signal driver 13 applies a drive voltage (for example, 5 V) higher than the common voltage Vcom to the pixel electrode 24. To do.

  In the present embodiment, the distance between the common electrode 28 and the pixel electrode 24 is smaller than the distance between the common electrode 25 and the pixel electrode 24. As an example, when the distance a between the common electrode 28 and the pixel electrode 24 is about 4 μm and the distance (cell gap) b between the common electrode 25 and the common electrode 28 is about 3 μm, the end of the common electrode 28 and the end of the common electrode 25 And the distance d on one side is increased by 1.35 μm or more. In this case, the oblique electric field applied between the common electrode 28 and the pixel electrode 24 is relatively larger than the lateral electric field applied between the common electrode 25 and the pixel electrode 24.

  Thereby, the orientation of the liquid crystal can be further stabilized. Specifically, the liquid crystal between the common electrode 25-1 and the pixel electrode 24 has a half bend alignment so as to be inclined in the same direction. Similarly, the liquid crystal between the common electrode 25-2 and the pixel electrode 24 has a half bend alignment so as to be inclined in the same direction. In the present embodiment, it is possible to suppress the generation of a liquid crystal alignment defect domain that has occurred in the comparative example.

[3. effect]
As described above in detail, in the fourth embodiment, the liquid crystal layer 23 is made of a p-type (positive) liquid crystal material, and aligns liquid crystal molecules substantially vertically in the state where an electric field is not applied. Further, the TFT substrate 21 is provided with a linear pixel electrode 24 and a common electrode 25 formed so as to surround or sandwich the pixel electrode 24 with a predetermined interval. In addition, the CF substrate 22 is provided with a common electrode 28 having substantially the same planar shape as the common electrode 25 and formed so as to at least partially overlap the common electrode 25. The distance between the common electrode 28 and the pixel electrode 24 is set smaller than the distance between the common electrode 25 and the pixel electrode 24.

  Therefore, according to the fourth embodiment, when an electric field is applied to the liquid crystal layer 23, the liquid crystal molecules take a half-bend alignment. Therefore, compared with the VA mode, the IPS / FFS mode, and the like, The response speed can be further increased.

  In addition, the oblique electric field applied to the liquid crystal layer by the common electrode 28 during the half bend alignment can be made larger than the lateral electric field applied to the liquid crystal layer by the common electrode 25. Thereby, since the orientation of the liquid crystal can be further stabilized, it is possible to suppress the generation of domains with poor liquid crystal orientation. As a result, the display characteristics can be further improved.

  Note that the second and third embodiments may be applied to the fourth embodiment.

[Fifth Embodiment]
In the fifth embodiment, the common electrode 25 is disposed below the pixel electrode 24 so that the distance between the common electrode 28 and the pixel electrode 24 is smaller than the distance between the common electrode 25 and the pixel electrode 24. .

  The layout diagram for one pixel is the same as FIG. 5 (without the reflection film) shown in the first embodiment. 24 is a cross-sectional view of the liquid crystal display panel 11 taken along line AA ′ shown in FIG. FIG. 25 is a cross-sectional view of the liquid crystal display panel 11 taken along line BB ′ shown in FIG. 24 and 25, illustration of the circularly polarizing plates 30 and 33 and the alignment films 26 and 29 is omitted. When the reflective film 46 is provided (that is, in the case of a semi-transmissive type), the reflective film 46 is disposed in a level layer different from the common electrode 25.

  The common electrode 25 (common electrodes 25-1 to 25-4) is disposed below the pixel electrode 24. In the configuration example of FIGS. 24 and 25, the common electrode 25 is disposed on the insulating film 45. The common electrodes 25-1 and 25-2 are formed so as to cover the signal line SL in the planar projection.

  The distance c between the pixel electrode 24 and the common electrode 28-2 is set to be smaller than the distance a between the pixel electrode 24 and the common electrode 25-2. Similarly, the conditions of the common electrodes 25-1, 25-3, 25-4, 28-1, 28-3, 28-4 are also set so as to satisfy the same conditions as the common electrodes 25-2, 28-2. Is done.

  The conditions for setting c <a are as follows: (1) the width of the common electrode 28 is made larger than the width of the common electrode 25; and (2) the depth of the common electrode 25, that is, the bottom surface of the pixel electrode 24. This can be achieved by increasing the vertical distance to the top surface of the plate. Alternatively, the condition of c <a may be satisfied by mainly adjusting the depth of the common electrode 25 after setting the widths of the common electrode 25 and the common electrode 28 to predetermined values.

  As described above in detail, according to the fifth embodiment, the oblique electric field applied to the liquid crystal layer by the common electrode 28 can be made larger than the lateral electric field applied to the liquid crystal layer by the common electrode 25 during half-bend alignment. it can. Thereby, the same effect as the fourth embodiment can be obtained. Further, by adding the level of the common electrode 25 to the method for setting the condition of c <a, the design for making the oblique electric field larger than the lateral electric field becomes easy.

  Each of the above embodiments may be realized as a transflective liquid crystal display panel including a reflective region and a transmissive region, or may be realized as a transmissive liquid crystal display panel including no reflective region (reflective film 46). Good.

  Moreover, in each said embodiment, the structural example of the liquid crystal display panel 11 provided with the circularly-polarizing plates 30 and 33 is shown. However, the present invention is not limited to this, and the polarizer may be configured by omitting the phase difference plates 31 and 34.

  The present invention is not limited to the above embodiment, and can be embodied by modifying the constituent elements without departing from the scope of the invention. Further, the above embodiments include inventions at various stages, and are obtained by appropriately combining a plurality of constituent elements disclosed in one embodiment or by appropriately combining constituent elements disclosed in different embodiments. Various inventions can be configured. For example, even if some constituent elements are deleted from all the constituent elements disclosed in the embodiments, the problems to be solved by the invention can be solved and the effects of the invention can be obtained. Embodiments made can be extracted as inventions.

  DESCRIPTION OF SYMBOLS 10 ... Liquid crystal display device, 11 ... Liquid crystal display panel, 12 ... Scan driver, 13 ... Signal driver, 14 ... Common voltage supply circuit, 15 ... Voltage generation circuit, 16 ... Control circuit, 17 ... Pixel, 18 ... TFT, 18 ... Switching element, 20 ... Back light, 21 ... TFT substrate, 22 ... CF substrate, 23 ... Liquid crystal layer, 24 ... Pixel electrode, 25 ... Common electrode, 26, 29 ... Alignment film, 27 ... Color filter, 28 ... Common electrode, 30, 33 ... Circularly polarizing plate, 31, 34 ... Retardation plate, 32, 35 ... Polarizing plate, 40 ... Storage capacitor line, 41, 45, 47 ... Insulating film, 42 ... Semiconductor layer, 43 ... Source electrode, 44 ... Drain electrode, 46 ... reflective film, 48 ... contact plug.

Claims (10)

First and second substrates disposed opposite to each other;
A liquid crystal layer sandwiched between the first and second substrates, made of a p-type liquid crystal material, and having a vertical alignment without applying an electric field;
A pixel electrode provided on the first substrate and extending in a first direction ;
The pixel electrode is provided on the first substrate and includes first and second electrode portions each extending in the first direction, wherein the first and second electrode portions are in the second direction orthogonal to the first direction. A first common electrode , spaced apart on both sides of the
A second common electrode provided on the second substrate and including third to fifth electrode portions each extending in the first direction ;
Equipped with,
Each of the third and fourth electrode portions at least partially overlaps the first and second electrode portions in a planar projection;
The liquid crystal display device according to claim 5, wherein the fifth electrode portion at least partially overlaps the pixel electrode in planar projection .   The distance between the third electrode portion and the pixel electrode is smaller than the distance between the first electrode portion and the pixel electrode,
  The liquid crystal display device according to claim 1, wherein a distance between the fourth electrode portion and the pixel electrode is smaller than a distance between the second electrode portion and the pixel electrode.   First and second substrates disposed opposite to each other;
  A liquid crystal layer sandwiched between the first and second substrates, made of a p-type liquid crystal material, and having a vertical alignment without applying an electric field;
  A pixel electrode provided on the first substrate and extending in a first direction;
  The pixel electrode is provided on the first substrate and includes first and second electrode portions each extending in the first direction, wherein the first and second electrode portions are in the second direction orthogonal to the first direction. A first common electrode, spaced apart on both sides of the
  The third and fourth electrode portions are provided on the second substrate and each extend in the first direction, and each of the third and fourth electrode portions is at least one of the first and second electrode portions in a planar projection. A second common electrode partially overlapping,
  Comprising
  The distance between the third electrode portion and the pixel electrode is smaller than the distance between the first electrode portion and the pixel electrode,
  A distance between the fourth electrode portion and the pixel electrode is smaller than a distance between the second electrode portion and the pixel electrode. 4. The liquid crystal display device according to claim 1 , further comprising a driving circuit that applies the same voltage to the first common electrode and the second common electrode. 5. The width of the third electrode portion is larger than the width of the first electrode portion,
5. The liquid crystal display device according to claim 1 , wherein a width of the fourth electrode portion is larger than a width of the second electrode portion . The end of the third electrode portion is disposed on the pixel electrode side from the end of the first electrode portion in planar projection,
6. The liquid crystal display device according to claim 1 , wherein an end of the fourth electrode portion is disposed closer to the pixel electrode than an end of the second electrode portion in a planar projection . The liquid crystal display device according to claim 1, wherein the first common electrode is disposed in a level layer below the pixel electrode. A signal line for supplying a driving voltage to the pixel electrode;
The liquid crystal display device according to claim 1, wherein the first common electrode is disposed so as to cover the signal line.   9. The liquid crystal display device according to claim 1, further comprising first and second circularly polarizing plates arranged so as to sandwich the first and second substrates.   The liquid crystal display device according to claim 1, further comprising a reflective film that is provided on the first substrate and reflects incident light.